<!DOCTYPE html>
<html>
  <body>
    <iframe src="data:text/html,<body spellcheck=false>xx</body>"></iframe>
    <script>
      onload = function() {
        var i = document.querySelector("iframe");
        var d = i.contentDocument;
        var w = i.contentWindow;
        d.designMode = "on";
        i.focus();
        d.body.focus();
        w.getSelection().collapse(d.body.firstChild, 2);
      };
    </script>
  </body>
</html>
